1. Field of the Invention
The present invention relates to vehicles suitable for traveling over rough terrain.
2. Description of the Related Art
Vehicles suitable for traveling over rough terrain are conventionally known. Included among such vehicles are an all-terrain vehicle (ATV) and a recreational off-highway vehicle (ROV). For example, U.S. Pat. No. 7,461,851 B2 and U.S. Pat. No. 6,695,329 B2 each disclose an ROV including upper arms, lower arms, a body frame, rear wheels, and shock absorbers. The rear wheels are supported by the body frame via the upper and lower arms that are movable members. The shock absorbers are connected to the body frame and the lower arms.
In general, the larger the operating range or stroke of a shock absorber, the greater the shock-absorbing performance of the shock absorber. The operating range of a shock absorber varies depending on arm lengths of upper and lower arms measured in the width direction of a vehicle. As used herein, the term “arm length” refers to a distance between a connection of an upper or lower arm with a body frame, and a connection of this arm with a wheel. This means that the longer the arm lengths, the larger the operating range of a shock absorber.
The ROV disclosed in each of U.S. Pat. No. 7,461,851 B2 and U.S. Pat. No. 6,695,329 B2 includes the upper and lower arms connected to the body frame extending in the front-rear direction of the vehicle. A possible approach to increasing the arm length in such a structure is to dispose the wheel farther outward in the width direction of the vehicle. Unfortunately, such an approach results in an increase in the widthwise length of the vehicle. Another possible approach is to dispose the connections of the upper and lower arms further inward in the width direction of the vehicle. However, components, such as an engine, are disposed inward of the upper and lower arms in the width direction of the vehicle. This makes it difficult to dispose the connections of the upper and lower arms, which are movable members, farther inward in the width direction of the vehicle.
As a possible solution to these problems, U.S. 2012/0223500 A1 discloses a vehicle including forward connections and rearward connections through which the upper and lower arms are connected to the body frame, with the rearward connections disposed inward of the forward connections in the width direction of the vehicle. This arrangement makes it possible to increase arm lengths without having to increase the widthwise length of the vehicle.
However, in the vehicle of U.S. 2012/0223500 A1, the connections between the upper arms and the body frame and the connections between the lower arms and the body frame are located at substantially the same positions in a plan view of the vehicle. Thus, the body frame must be arranged so that the connections between the upper arms and the body frame and the connections between the lower arms and the body frame are substantially aligned along the up-down direction of the vehicle. As a result, the upper and lower arms have limited flexibility in terms of mounting positions thereof.